attempting to join friends server results in error message

When trying to play with my friends on their server, I get the message "you are not invited to play on this server". This happens every time I try, despite being invited multiple times and both me and my friend reseting Minecraft. If I do get invited, it gives me the message "cannot connect to world". The first message usually happens if you have been kicked. However, my friend doesn't know how to use /kick. And if he did, it would be fixed by reseting the server. This problem started when 1.16.0 was added. Both me and my friend are on the latest version.